Field of the Disclosure
Embodiments of the present disclosure generally relate to a showerhead design having a reflector plate with a gas injection insert for radially distributing gas.
Description of the Related Art
Semiconductor substrates are processed for a wide variety of applications, including the fabrication of integrated devices and microdevices. One method of processing substrates includes depositing oxygen radicals on an upper surface of the substrate. For example, Applied Materials, Inc., of Santa Clara, Calif., offers a RadOx® process that heats the substrate with lamps and injects hydrogen and oxygen into a processing chamber. The gases form radicals when they strike the surface of the substrate to form a layer on the substrate, e.g., oxygen radicals form a silicon dioxide layer on a silicon substrate.
Current processing chamber showerheads used for radical oxygen deposition on 300 mm substrates have limited deposition control, resulting in poor processing uniformity. For example, low processing chamber pressure requirements for radial oxygen deposition and current showerhead designs result in gas reaching the substrate at a high velocity. The high velocity of the gas causes impingement on the substrate and prevents the gas from being adequately heated. On the other hand, oxygen radicals generated from combustion quickly recombine to create a short life cycle for the oxygen radicals. Therefore, the limited deposition control due to the high velocity of the gas combined with the short life cycle of oxygen radicals results in greater deposition at the center of the substrate, and poor deposition at the edges of the substrate.
Therefore, there is a need for an improved showerhead design that provides deposition control for more uniform deposition throughout the substrate, i.e., from the center to the edge.